Data_Sheet_1_Selection Signatures in Chinese Sorghum Reveals Its Unique Liquor-Making Properties.docx

Chinese sorghum (S. bicolor) has been a historically critical ingredient for brewing famous distilled liquors ever since Yuan Dynasty (749 ∼ 652 years BP). Incomplete understanding of the population genetics and domestication history limits its broad applications, especially that the lack of genetics knowledge underlying liquor-brewing properties makes it difficult to establish scientific standards for sorghum breeding. To unravel the domestic history of Chinese sorghum, we re-sequenced 244 Chinese sorghum lines selected from 16 provinces. We found that Chinese sorghums formed three distinct genetic sub-structures, referred as the Northern, the Southern, and the Chishui groups, following an obviously geographic pattern. These sorghum accessions were further characterized in liquor brewing traits and identified selection footprints associated with liquor brewing efficiency. An importantly selective sweep region identified includes several homologous genes involving in grain size, pericarp thickness, and architecture of inflorescence. Our result also demonstrated that pericarp strength rather than grain size determines the ability of the grains to resist repeated cooking during brewing process. New insight into the traits beneficial to the liquor-brewing process provides both a better understanding on Chinese sorghum domestication and a guidance on breeding sorghum as a multiple use crop in China.

中国高粱（S. bicolor）自元代（距今749至652年）起，便是酿制知名蒸馏酒的核心历史原料。当前对其群体遗传学（population genetics）与驯化历史（domestication history）的认知不足，限制了其广泛应用；尤其由于缺乏酿酒性状背后的遗传学知识，难以建立高粱育种的科学标准。为阐明中国高粱的驯化历史，本研究对采自16个省份的244份中国高粱品系开展了全基因组重测序（re-sequencing）。研究发现，中国高粱可划分为三个具有显著地理分布特征的遗传亚群，分别命名为北方群、南方群与赤水群。本研究进一步对这些高粱种质（accessions）进行了酿酒性状鉴定，并挖掘出与酿酒效率相关的选择印记（selection footprints）。本次研究鉴定到一个重要的选择性清除（selective sweep）区域，该区域内包含多个与籽粒大小、颖壳厚度及花序结构相关的同源基因。研究结果同时表明，决定酿酒过程中籽粒耐反复蒸煮能力的并非籽粒大小，而是颖壳强度。本研究针对酿酒有益性状所获得的新认知，不仅加深了对中国高粱驯化历史的理解，同时也为中国多用途高粱的育种工作提供了科学指导。